This is certainly a very good reason to not put your work account on your personal phone, but my primary reason not to is that it's my device and I pay for the service. If my company needs me to be available beyond my 9-5 workday, they can pay for it.
If there's an emergency, they can always call, but I don't like being "always on".
If there's an emergency, they can always call, but I don't like being "always on".